Trouble installing macOS 10.14 Mojave

[exoulster]

Hello,

I am having trouble installing the package under macOS 10.14 Mojave.

The error message is quite vague
Error: Could not find tools necessary to compile a package

llvm 7.0 was installed via brew

$ /usr/local/opt/llvm/bin/clang --version
clang version 7.0.0 (tags/RELEASE_700/final)
Target: x86_64-apple-darwin18.0.0
Thread model: posix
InstalledDir: /usr/local/opt/llvm/bin

~/.R/Makevars is also properly set up

$ cat ~/.R/Makevars 
CXX = /usr/local/opt/llvm/bin/clang
CXXFLAGS = -I/usr/local/opt/llvm/include -fopenmp
LDFLAGS = -L/usr/local/opt/llvm/lib -fopenmp=libiomp5

But when I run this in RStudio, I get the following message

> library(devtools)
> install_github('zelazny7/isofor')
Downloading GitHub repo zelazny7/isofor@master
Error: Could not find tools necessary to compile a package

R version 3.5.1

> version
               _                           
platform       x86_64-apple-darwin15.6.0   
arch           x86_64                      
os             darwin15.6.0                
system         x86_64, darwin15.6.0        
status                                     
major          3                           
minor          5.1                         
year           2018                        
month          07                          
day            02                          
svn rev        74947                       
language       R                           
version.string R version 3.5.1 (2018-07-02)
nickname       Feather Spray  

Plus, everything works fine on macOS 10.13. So I suspect it has something to do with os?

Thanks!

[gravesee]

I had the same issue when I upgraded to Mojave. I just commented the repos copy of src/Makevars and also commented out everything in my ~/.R/Makevars. It now compiles using gcc without the openmp flags passed.